Speed-regulator system



Sept. 28,1926; 1,601,330-

S. A. STAEGE SPEED REGULATOR SYSTEM Filed Feb. 19, 1921 k I\ WITNESSES: INVENTOR 5fe 9/7e/7/Z Siege l7. 4% W VMW ATTORNEY Patented Sept. 28, 1926.

. UNITED STATES PATENT OFFICE.

STEPHEN A. STAEGE, OF PITTSBURGH, PENNSYLVANIA, ASSIGNQR T WESTING- HOUSE ELECTRIC & MANUFACTURING COMPANY, A CORPORATION OF PENNSYL- VANIA.

SPEED-REGULATOR SYSTEM.

Application filed February 19, 1921.- Serial No. 446,464.

My invention relates to speed-regulator systems and it has special relation to systems adapted to maintain a substantially constant-speed ratio between a plurality of movable members.

. One object of my invention is to provide a speed-regulator system of the above-indicated character comprising simplified apparatus, which shall be efficient and reliable in operation and free from hunting action. Another object of my invention is to progeneran auxiliary frequency-changer. The other winding of the auxiliary freqency changer is connected to a frequency-changerthat is common to all the sets of rotatable members and is adapted to supply a constant fre-.

quency to all the auxiliary frequency changers. Anydifi'erenoe in frequency between the constant frequency-changer and the individual frequency-changers driven by the rotatable members will be recorded by a consequent movement of the auxiliary freqency-changer, constituting an electricdifferential, toset in motion a train of mechanism that is ada ted to correct the propelling-motor speed in accordance with .the abnormal load thereupon,

Iii the present application, in place of a motor-generator set to constitute the frequency-changer common to all rotating units, I provide a generating vacuum tube or oscillation generator having a circuit of sustained currents for each rotatable unit.

The present application also includes a variable condenser associated with each vacuum-tube device, said condensers being mounted upon a master rod, through the 1 the 'the shaft 13 of this differential.

medium of which the capacitance value of the circuit of each of the vacuum-tube devicesmay be simultaneously altered. In addition, each condenser has associated therewith a gear wheel by which the position of the normally stationary member of the variable condenser may be altered so that each unit may be varied individually. Thus, the above-mentioned mechanical speedchanging device is dispensed with.

Reference may now be had to the accompanyrng drawing, wherein the single figure 1s a diagrammatic illustration of the circuits and apparatus embodying my invention, as applied to a pluralit of rotatable units.

In the present app ication, for convenience of description, the auxiliary frequencychanger referred to above Wlll be herein deslgnated as an electric differential. Also, inasmuch as the present invention involves circuits and apparatus common to each of the rotating units, it will be described with reference to one unit only, and the illustrated duplicated parts will be given like reference numerals.

The rotatable unit is diagrammatically ilf lustrated by a roll 1. The roll 1 is propelled by a motor 2 having an armature 3 and a shunt field-magnet winding 4. Included in field-magnet-winding circuit is the rheostat 5, to which more detailed reference will hereinafter be made.

Directly connected to the shaft 6 of roll 1 is one Winding of a frequency-changer 7, which supplies a frequency directly proportional to the speed of rotation of the roll to one of the windings 8 of an electric differential. The other winding 9 of the electric differential is adapted to have a substantially constant frequency applied thereto from an oscillatory generator tube 11' through a transformer 12. The operation of this electric. differential is exactly equivalent to the auxiliary frequency-changer or differential 18 of my copending application referred to above.

As in that application, a double-acting lever 14 carrying contact arms 15 and 16, respectively, is rictionally mounted upon Contact. arms 15 and 16 respectively co-operate with terminals 17 and 18 to complete acircuit to the one or the other of difierential fieldmagnet windings 19 and 20 of pilot motor 22, in accordance with the direction of movement of the differential. This action will effect a corres onding movement of the contact arm 23 o the rheostat 5, through gearing 24, to govern the excitation of the propelling motor 2. The 'motor-operated rheostat 5 is adapted to have a normal step-bystep movement through the operation of the oppositely-acting electromagnets 25 and 26, which are connected, in parallel relation, across the armature circuit of the pilot mo tor 22. a

Also mounted upon the shaft 13 of the differential is' an inertia-responsive device 27, which is adapted to accelerate the normal step-by-step action of the rheostat motor 22 under certain conditions, and which also constitutes an anti-hunting device for the regulator. The accelerating action may be accomplished by the arm 27 which projects between opposite sets of contact terminals 23 and 29 to control the energization of the coil of electromagnetic switch 31 to interrupt the circuit to the electromagnetic coils 25 and 26 and thereby render them ineffective.

' Hence, the' pilot motor 22 will then have a continuous movement in the direction necessary to effect a speed correction of the motor 2, until the inertia-responsive device acquires the rotational speed of the electric differential, whereupon, the circuit to the coil of switch 31 will be broken to de-ener- ,gize this switch. This action will occurjust prior to the attainment of normal load conditions upon the propelling motor, with the result that the motor will drift into its normal condition without any hunting action. The apparatus and mode of operation thereof are both fully set forth in the copending application referred to above and, hence, no further description will be given herein.

The present invention is more particularly concerned with the constant-frequency generator or thermionic tube 11 and the means for obtaining varying speeds of the individual units. As illustrated in the drawing, the constant frequency generator 11 comprises a vacuum tube having a cathode element 32, a filament element 33 and a plate element 34. The'plate-filament, or output, circuit herein shown includes a battery 35, one coil of the transformer 12 and an inductance element 36. Connected across the inductance 36 is a variable condenser- 37 having a normally stationary portion 38 and an electrically co-operating movable portion 39.

One of the vacuum-tube devices 11 is provided' for each rotatable unit. Consequ ntly, there is also one of the variable con ensers 37 for each rotatable unit. Since it, at times, becomes desirable, particularly in rolling-mill applications, to change the speed of all the rotatable units simultaneously by a definite percentage, the present invention contemplates connecting all of the movable dles 42, by means of which the shaft 41 may be revolved to simultaneously control all of the units.

Also, it frequently becomes desirable to vary the speed of each unit individually with respect to the remaining units. To this end, the normally stationary portions 38 of each variable condenser-37 have a segmented gear wheel 43 associated therewith. Co-operating with each of the gear wheels 43 is a pinion 44, which has a handle 45 connected thereto. Hence, if it becomes desirable to vary the speed of one unit with respect to the neighboring or remaining units, this change may be accomplished by changing the position of the normally stationary plates 38 so that the capacity of the individual condenser may be varied.

It will be apparent that effecting either of these changes will vary the reactance of the output circuit of the constant-frequency generator which is applied to'one side of the electric differential. Any deviation of the frequency applied to the opposite side of the differential from the frequency-changer 7, driven by the roll 1, from the constant frequency will cause an operation of the differential to correct the excitation of the pro pelling motor 2 to change the frequency 01 the frequency generator 7 to correspond to that of the constant-frequency generator 11. 3

In other words, when beginning an operation the capacity of the output circuit of each constant frequency generator 11 is so set that the rotatable units will be operated at a constant predetermined speed ratio. This condition, consequently, requires that the excitation of the propelling motor 2 for each unit shall correspond to that speed ratio.

lVhen these conditions have been determined, and the millvis' in operation, this constant-speed ratio is maintained for each roll, respectively, by the operation of'the individual electric differentials. Since a constant frequency is applied to one side of the electric differential and a frequency proportional to the speed of the unit (which frequency must correspond to the constant frequency under normal conditions), is applied to the other side thereof, any deviation of the frequency on either side of the differential will cause a rotating movement of the differential shaft 9 to energize the pilot motor 22 to correct the excitation of the motor 2. If this change in frequency occurs by reason of an abnormal load upon the rotating unit, the correction made will be such as to bring the variable frequency into accordance' with the constant frequency; However, if the variation occurson the constant-frequency side of the differential, which change will be at the will of the operator, the correction made will be such as to bring the variable frequency into accordance with the newly applied constant frequency. This result may be accomplished only by correspondingly changing the speed of the rotatable unit 1. Hence, the correction in question will take eflect upon the propelling motor 2 of the rotatable unit 1 to raise or lower its excitation to thereby govern the rotational speed of the unit 1. In the illustration herein the secondary winding 9 of the electric differential, or diffelential relay, is illustrated as having a single-phase current applied thereto from the constant source and a polyphase current applied to the primary winding thereof from the roll-actuated frequency-changer. Obviously, these relations may be reversed without impairing the operativeness of the hereindescribed system.

Inasmuch as the accelerating and antihunting devices are described in detail in my copending application referred to above, no detailed reference will be made to their operation here, since the principles of the present invention are applicable to other systems of regulation, as well as to that to which it is shown applied.

Modifications in the system and arrangement and location of parts may be made within the spirit and scope of my invention, and such modifications are intended to be covered by the appended claims.

I claim as my invention 1. In a regulator system, the combination speeds of said dynamo-electric machines.

2. In a regulator system, the combination with a plurality of dynamo-electric machines and regulator means associated therewith, of a plurality of oscillation generators also associated therewith and co-operating with said regulator means, and means for jointly or individually varying the capacities of the output circuits of said generators.

In a regulator system, the combination with a plurality of rotatable members, a

propelling motor for each of said members having a motor-operated rheostat in circuit therewith, said rheostat being adapted for operation to vary the excitation of the associated motor, a plurality of electric differentials for controlling the motor-operated rheostats of a vacuum-tube frequency-generating device associated with each differential and connected thereto, said device having an output circuit, means for 'ointly and for individually controlling saidmachines by varying the reactance of said circuit. In testimony whereof, I have hereunto subscribed my name this 11th day of February, 1921.

STEPHEN A. STAEGE. 

